1. Field of the Disclosure
The present disclosure relates to an apparatus and method for canceling interference in a communication system supporting a multi-user Multiple-Input Multiple-Output (MIMO) scheme, and more particularly, disclosure to an apparatus and method for adaptively canceling interference in a communication system supporting a multi-user MIMO scheme.
2. Description of the Related Art
Communication systems have evolved to support high data rates in order to satisfy demands for wireless data traffic, which continuously increases. For example, a communication system has evolved to enhance spectral efficiency and increase channel capacity based on various schemes such as a MIMO scheme, and the like in order to increase a data rate.
In a communication system, cell edge STAtions (STAs) which are located at a cell edge region which is far from a cell center in which a Signal-to-Noise Ratio (SNR) is low, or a Carrier-to-Interference and Noise Ratio (CINR) is low due to significant impact of interference from a Base Station (BS), which is located at a neighbor cell, may decrease system performance of the communication system.
Thus, in a communication system, various schemes such as an Inter-Cell Interference-Coordination (ICIC) scheme, a Coordinated Multi-Points (CoMP) scheme, an interference cancellation scheme, and the like have been developed in order to increase transmission efficiency for the cell edge STAs.
In a downlink in a communication system supporting a multi-user MIMO scheme, an Access Point (AP) may transmit data to a plurality of STAs. So, if the AP provides a service to the plurality of STAs, the AP may provide high throughput.
In the downlink in a communication system supporting the multi-user MIMO scheme, the AP applies a pre-coding matrix which is generated based on downlink Channel State Information (CSI) feedback to a transmitted signal.
Meanwhile, a downlink in a communication system supporting a multi-user MIMO scheme has been modeled by assuming that only a desired signal is received in an STA, since a perfect pre-coding is applied to a transmitted signal. However, in an actual channel situation of the downlink in a communication system supporting the multi-user MIMO scheme, there are a quantization error and a channel estimation error, so it is difficult that a perfect pre-coding is applied to the transmitted signal due to the quantization error and the channel estimation error.
If a pre-coding matrix which is generated based on CSI in which an error is included is applied to a transmitted signal, information necessary for each STA, e.g., a desired signal and unnecessary information which is for other STAs, e.g., interference signals are received in each STA. These interference signals result in a decreased receiving rate in each STA.
Thus, in a communication system supporting the multi-user MIMO scheme, various interference cancellation schemes have been proposed in order to solve situations which may occur due to interference signals.
However, the various interference cancellation schemes proposed in a communication system supporting the multi-user MIMO scheme have high processing complexity, and are inefficient since an interference cancellation operation must always be performed even though an interference signal does not influence detection of a desired signal. The various interference cancellation schemes require a large amount of processing computation and power, since an interference cancellation operation is always performed even though an interference signal does not influence detection of a desired signal.
Thus, there is a need for a new scheme of canceling interference thereby decreasing processing complexity, processing computation amount, and power consumption in a communication system supporting a multi-user MIMO scheme.